This site is 100% ad supported. Please add an exception to adblock for this site.

Chemisty Chapter 2


undefined, object
copy deck

who was Democritus?        


greek phiosopher




what did Democritus propose? 


that all matter, the stuff that makes up the world around us, is actually composed of tiny, invisible particles. 


what did Democritus call these tiny particles?  


or atoms 


what did Aristotle come up with

what were they? 


4 elements

fire= hot

earth= cool/heavy




Who was right? 


since Aristotle was more famous he won

and his ideas carried through the middle ages. 


John Dalton

    where was he from?

    what was his job? 






What did Dalton come up with?

what was it? 


Dalton's Atomic Theory

combined ideas 


what are the 4 main postulates of this theory? 


all matter is made of tiny invisable particles calld atoms

atoms of the same elemnt are identical  ... different elsments are different.

different elements combined in whole number ratios form a compound.

chemical re


what did Ben Franklin do? 


made electricity  









what did Michael Faraday do? 

what did he "invent" 


showed electricity in an atom 



What is Faraday the father of  



what is a cathode Ray Tube?

glass tube that has been evacuated of air

it has charged plates on wither end of the tub.



what side of cathode ray tube is positve 


cathode side 

what side of the cathode ray tube is negative
anode side
J.J Thomson

had the gas dischraged tube to show they were made up of egaive charged particles

he measured how the cathode rays wer deflected 

what is a particle

and who discovered it? 


 J.J Thomson

Robert Millikan

h was able to dermine the charge on the electron

    calculate the mass(very small) 

what is the oil drop experiment
indirect measuring to determine the charge of the electron.
what was Thomson model of an atom

Plum Pudding model


what was he plum pudding model

lectrons were andomly spread throughour t poxitivly charged thing

aka a chocolate chip cookie 




what are the charges for these? 




nucleus = ?



atomic number

number of all the protons in an atom

id of matter

distinguishes one type of atom from another 

atomic mass
number of protons and neutrons

who has the decimal?

atomic mass or number 

atomic mass
number of neutrons =______ - ______
mass number - atomic number
what is atomic mass?
the weighted average mass of all the naturally occurring isotopes f an element
what is an isotope?

atoms of certain element

may contain different numbers of neutrons  

nucleus is what
 neutrons and protons
what is the strong nuclear force?

forces of attraction within particles in the nuceus

* neutrons make the nucleus "stick" together 

what is Radioactivity?
spotanus release of energy resulting in a change in the neulcues

alpha is _________ dangerous

how can it be stopped?

it is the result of what? 


it can be stopped by clothing and paper

of 2 protons and 2 neutrons leaving the nuclues 

Beta is what
high sped stream of electrons that are leaving the nucleus

Gamma is what

it is _______ dangerous  

highly excited forms of energy

most dangerous only lead and concrete can stop it  

what is a nuclear reaction
reactions that change an atoms necleus
what are the two types of reactions
alpha decay and beta decay
what did Michael Faraday show?
 showed the electricity in an atom
what side of cathode ray tube is positive
who discovered particles -> electrons
J.J Thomson

by measuring how the cathode rays were deflected he realized what 


J.J Thomson 

1. greater the mass, less the deflection

2. greateer the charge, the greater the deflection  

what was the oil drop experiment?
indirect measuring to determine the charge of the electrons

Deck Info